Medical Devices Etc Research Articles

Biocompatible Nanogenerators Explored to Generate Electricity

In this era of ‘Smart technologies’ there is a demand for power generation using innovative eco- economical technologies. With increasing population, the use of electric power is also increasing. But we know that the resources are limited to generate electricity and this has led to the energy crisis. Under this scenario, we need to explore non-polluting eco-economical methods to generate electricity. To meet this, a smart material such as piezoelectric materials are subjects of extensive research and development and are continuously finding newer applications. The piezoelectric materials convert mechanical energy into electrical energy. Mechanical energy can be extracted from kinetic energy of vehicles, footsteps, wind currents, breathing etc. Presently, their diverse applications include flexible, biocompatible and energy efficient smart materials used as nanogenerators. In this article we are reporting the making of a prototype using fish scales as piezoelectric material which can convert energy from surroundings like sound energy, wind currents etc into electrical energy. The energy converted to electrical energy can be used for charging of mobile phones lightning streets, portable medical devices etc. This will help reduce the bio-waste and produce new biocompatible nanogenerators which exhibit a feasible source of continuous power for various self- powered devices.

Models and filtering of circular images with harmonic components of the covariance function

Nowadays, image processing problems are becoming increasingly important due to development of the aerospace Earth monitoring systems, medical devices etc. But the most of the image processing works deal with images defined on rectangular two-dimensional grids or grids of higher dimension. In some practical situations, images are set on a circle. The peculiarity of such images requires its consideration in their models. In the early works of the authors, several autoregressive models of such images were proposed. However, these models can generate images with positive covariation functions. Sometimes the impact of the external environment and internal features of the object lead to the presence of harmonic components. For example, facies, eye, virus, sunflower, etc. To represent such images, complex roots are necessary in characteristic equation of autoregressive model. In the present paper, autoregressive models of circular quasiperiodic images are considered. The expressions of their covariance functions are given. The pseudo-gradient algorithms for model identification, and images forecasting and filtering are proposed.

Free-Standing Poly (Acrylic) Acid / Potassium Hydroxide Based Polymer Electrolyte Membrane As Electrolyte for Printed Zinc/Silver Oxide Batteries

Printable batteries have attracted great attention as an emerging power source for wearable electronics such as RFID tags, implantable medical devices etc. The need for environmentally friendly batteries with high energy density has led to the development of partially printed primary zinc-silver oxide batteries. It has been reported that printed Zn/Ag2O systems have low cost, lightweight and easy processing methods. A free-standing polymer membrane (FSM) made up of poly(acrylic) acid, poly(ethylene)oxide and potassium hydroxide has not been systematically studied for its application as an electrolyte in printed batteries. In this work, we have prepared and characterized FSM for its compatibility to be used as an electrolyte in a Zn/Ag2O systems by employing electrochemical, microscopic and spectroscopic techniques. Cyclic voltammetry is used to understand the electrochemical processes going on the electrode, charge-discharge curves are reported to present the specific capacity of the battery. For printed electrodes, ionic conductivity is of the order of 10-3 siemens.cm-1 transference number (Zn+), for Zn|| FSM||Zn (Printed zinc (Zn)) cell structure is 0.247.Further, a comparative study of FSM behavior with printed zinc and the zinc metal foil electrodes is done with an intention to understand the electrochemical behaviour of zinc electrodes in Zn/Ag2O all-solid-state battery device. Specific capacities of 3.604 and 2.495 mAh.cm-2are achieved for batteries having zinc printed and metal foil electrodes respectively. Though printed electrodes demonstrated better specific capacity, its repeatability remains an issue. Further work is being done to address the issue of electrode recyclability and performance repeatability.

Comparative analysis of biofabricated silver nanoparticles as antibiofilm agents on Pseudomonas aeruginosa

Microbial cells in the biofilm were characterized with significant features like antimicrobial resistance and bio fouling properties, which make them distinguishable from their planktonic forms. Although many antimicrobial drugs and antibiotics were reported for biofilm inhibition and dispersal, these compounds had limited applications because of drug resistance. Development of antibiofilm agents which could overcome the drug resistant bacteria had been a challenge over the years. In order to overcome development of drug resistance, silver nanoparticles were being used, to coat the medical devices. This strategy, though successful to some extent, suffer with toxic effects on eukaryotic cells in application. Hence there arises a need to explore natural compounds with antibiofilm activity. Natural products established as antibacterial agents were also found to have quorum quenching activity. Garcinia (Garcinia cambogia) and Ginger (Zingiber officinale) extracts were observed to possess quorum quenching activity in the lab, therefore used for biofabrication to enhance the antimicrobial activity of silver nanoparticles. Pseudomonas aeruginosa being a most potent biofilm forming bacteria in various environments, like infections, food spoilage and bio fouling in medical devices etc. The study aimed to figure out a novel antibiofilm agent, which could inhibit or eliminate biofilms by using a combination of biologically synthesized nanoparticles and natural quorum quenching agents. Comparative analysis of bio fabricated nanoparticles on the inhibition and dispersal of Pseudomonas biofilms was performed with non fabricated nanoparticles using microtiter based assay, followed by SEM and Flow cell cytometry techniques. Fabricated GNP (fGNP) had showed 17.9% more inhibition which indicates - 2 fold enhancement in biofilm inhibition activity. Similarly 9.45% enhancement was found in dispersal activity by fGNP. These results were encouraging us to improve upon the combinatorial approach and to formulate an ideal antibiofilm agent with minimal scope for emergence of antimicrobial resistance.

Kinetic Energy Harvesting from Human Hand Movement by Mounting micro Electromagnetic Generator

A comprehensive review of design and experimentation is presented in this research paper on sustainable renewable energy scavenging from Human body movement using Micro electromagnetic kinetic energy harvester to powering wearable, portable electronics, implantable medical devices etc. The body location which is chosen as the harvester is human hand between elbow and shoulder. Human body harvest energy in two ways i,e, mechanical energy and thermal energy. Mechanical energy is of two kinds one is static energy and the other one is kinetic energy. Due to motion or displacement or enforcement excitation the kinetic energy is extracted. The electric charges which remains imbalance on the surface or within a material is static energy. Thermal energy is extracted from the dissipation of heat from human body. Human body parts and organs generate energy through two types of activities are voluntary and involuntary. The energy which are produced by voluntary activities are high as people intentionally does work by body motion, walk, run. The generated energy by involuntary organs like heart, breathing, artery are smaller compare to voluntary energy harvesting. One process of energy harvesting is by use of micro electromagnetic generator, flexible and stretchable piezoelectric, triboelectric, electromagnetic induction, PVDF cantilever mounting on human body. The harvester prototype is cylindrical magnet L40xD10 mm size which is mounted on human hand for energy harvesting. While in movement of hand the produced wave forms by magnetic generator are measured and recorded for calculation. Analyzing the received data it has been found that the generated power by micro electromagnetic vibration generator from movement of human hand are 319 RMS μW and 2.48 RMS mV with a frequency of 0.25 Hz and power density of about 2.48μW/cm³.

受託安全確保業務 : GVP省令に基づく医薬品・医療機器等の情報収集について( 医薬品安全性情報の収集)

受託安全確保業務 : GVP省令に基づく医薬品・医療機器等の情報収集について( 医薬品安全性情報の収集)

Effect of Lamination Angle and Thickness on Analysis of Composite Plate Under Thermo Mechanical Loading

Abstract Analytical formulation and solution of stress analysis of composite plate subjected to thermo mechanical loading for various ply orientation and thickness of lamina are studied. The main aim of the paper is to investigate how mechanical and thermo mechanical loading would affect the stress ratio and stress distribution of composite plate. The plate is composed of layers of glass-epoxy composite and the orientation of the layers is assumed to be antisymmetric about the neutral axis of the laminate. The plate is subjected to a combined mechanical loading of tensile force and moment along x direction. The thermo mechanical stress is calculated for different ply orientation and thickness ratio, subjected to a temperature change and mechanical loading. The effect of number of lamina and varying thickness of laminate on the stress ratio and stress distribution is studied. The results in this paper are obtained by use of MATLAB Programming and by Finite element software ANSYS 14. Results obtained from both the methods are compared. Such type of loading finds wide application in aircraft flying at high altitude, marine application, medical devices etc.

Interactions of manufactured silver nanoparticles of different sizes with normal human dermal fibroblasts

Silver compounds have been used for their medicinal properties for centuries. At present, silver nanoparticles (AgNPs) are reemerging as a viable topical treatment option for infections encountered in burns, open wounds and chronic ulcers. This study evaluated the in vitro mechanisms of two different sizes of AgNPs (4·7 and 42 nm) toxicity in normal human dermal fibroblasts. The toxicity was evaluated by observing cell viability and oxidative stress parameters. In all toxicity endpoints studied (MTT and lactate dehydrogenase assays), AgNPs of 4·7 nm were much more toxic than the large AgNPs (42 nm). The cytotoxicity of both AgNPs was greatly decreased by pre-treatment with the antioxidant N-acetyl-L-cysteine. The oxidative stress parameters showed significant increase in reactive oxygen species levels, depletion of glutathione level and slight, but not statistically significant inactivation of superoxide dismutase, suggesting generation of oxidative stress. Thus, AgNPs should be used with caution for the topical treatment of burns and wounds, medical devices etc, because their toxicity depends on the size, the smaller NPs being much more cytotoxic than the large.

Nondestructive analysis of dielectric properties: Application to ion beam irradiated tissue response microfibre

The aim of this work was to investigate the effect of 2.4 MeV proton irradiation on the dielectric property of polyethylene terephthalate (PET) microfibre nondestructively. The dielectric constant εd of single-microfibre has been measured as-such applying laser diffraction technique. Applying this methodology εd is found out to be slightly increases with proton fluence except at the fluence 1013 p/cm2 where material shows maximum crosslinking. The variations of the biological interaction with εd of PET material are correlated. Proton beam modified PET microfibre is therefore accepted to have further potential applications in radiation processing tissue response microfibre, fabrication of medical devices etc.

Effect of Elevated Temperatures on the Formability of AA2014 Thin-Walled Tube Ends

Thin-walled tubes are used in a number of industrial applications as interconnecting elements, in the pneumatic, hydraulic, and exhaust systems of machines, in the electrical and electronics industry, as connectors in medical devices etc. The end of the tubes should be formed into different shapes that will suit the need of the above mentioned applications. In most of the applications, the tube ends either will be expanded or converged. However, there is a limit to which these tubes are expanded or converged, which depends on the material property as well as the process used. In the present study, an effort has been made to expand tubes of AA2014 aluminum alloy, which is an aerospace alloy containing copper as one of its main constituent. Different heat treatment processes such as solutionizing, aging, and annealing have been done on the preform to enhance its formability. Due to the low ductility of AA2014 alloy, the tube has been expanded at elevated temperatures. Finite element analysis based simulation studies have been performed to minimize the number of experiments. The formability of the tube has been found to improve considerably at the elevated temperatures.